Even if there are direct links to the al-Qaeda-affiliated Caucus Emirate, what’s Obama going to do? My guess is a big fat nothing.

WASHINGTON — Investigators said the two Boston Marathon bombs were triggered by long-range remote controls for toy cars — a more sophisticated design than originally believed — bolstering a theory that the older suspect received bomb-making guidance on his six-month trip to Russia last year.

Tamerlan Tsarnaev, who died in a shootout with police last week, “more than likely got some instruction in Dagestan,” a federal law enforcement official said Wednesday.

The official said investigators continued to believe that Tsarnaev, 26, and his brother, Dzhokhar, 19, were radicalized in the U.S., and that no foreign terrorist group orchestrated the plot. […]

A joint FBI and Department of Homeland Security intelligence bulletin sent to state and local law enforcement Tuesday night suggested that the bombs’ triggering mechanism was more sophisticated than previously thought.

“The sophistication of the explosive devices is similar to what you might find on a battlefield, and I am concerned there is a person out there, either in the Chechen region or in the United States, who trained him,” Rep. Michael McCaul (R-Texas), chairman of the House Homeland Security Committee, said in a statement.

“For anyone to rule out a foreign connection at this time, I think is highly premature,” he said.